Research is proposed to determine the effect of two factors upon differential risks of alcohol (ethanol) abuse, viz., learned behavior and heredity. It is not known why some people after initial contact with alcohol can "take it or leave it", whereas other people continue to imbibe and eventually become "problem" drinkers. The conditions which create these differential outcomes are not well understood and the possibility exists that people have different sensitivities to the initial dosing (drink) and that this sensitivity may have an inherited basis. Furthermore, those whoa re more sensitive to their first drink and who find it aversive will not continue to drink, whereas those who have little aversion, or indeed, reinforcement from that first drink are more prone to continue self-administering alcohol. The conditioned place preference (CPP) paradigm is a sensitive method to test the balance between an animal's preference and aversion to a centrally-active drug. A majority of the literature indicates that when ethanol has been used in the CPP task, it has been shown to be aversive and it only becomes reinforcing after extended experience with the drug. Experimentation will allow an investigation as to the differences in initial sensitivity to ethanol in rats genetically-bred to drink large amounts of ethanol as compared to those who re genetically-bred to be ethanol non-preferring. Another series of experiments will serve to determine the effect of learned (discriminative) behavior upon the preference/aversion balance. These experiments will test the difference between a group of animals passively administered ethanol and a group of animals trained to recognize the interoceptive stimuli (internal effects) produced by ethanol. Ethanol has been reported to be biphasic in its action, as it produces stimulation in its early phase followed by sedation. Rats will be trained to discriminate the effects of ethanol at either the early or later phase and they will be tested in the CPP task. Results will allow for suggestive evidence as to which phase of ethanol's effects is more preferred and which is less preferred.